RE: We have two subsidiaries under one parent: can pick, pack and ship functionality be applied to one subsidiary, but not the other?
One subsidiary would prefer pick, pack, and ship functionality, while the other subsidiary would not prefer it and is content with simply going from sales order to fulfill.
Can we apply PPS to a subsidiary level, or better yet, a vendor level? Where we use PPS for certain orders based on the items on the sales order?
Maybe – You’ll have to wait for 2020.1 to do this at the subsidiary level I think.

Thank you Kevin, but I didn’t happen to see any notes regarding that on this blog here…
https://gurussolutions.com/blog/netsuite-20201-release-notes-feature-updates
Looks like subsidiary settings manager is a 2019.2 feature. I was mistaken.